Can I appear in DRDO exams while studying 4th year B.Tech? When the application forms will be issued? What is the syllabus for DRDO exams?

i am studying btech ECE....... can we write DRDO exams when we are in 4th year itself.....? If so then when the application forms will be issued....... i.e. In which month.......? And also what is the syllabus that we should prepare for this exam........?